I've experienced such issue many times and solved by increasing memory_limit = 256M
in php.ini OR adding define( 'WP_MEMORY_LIMIT', '256M' );
in wp-config.php
file (*If needed you can increase memory more than 256M
) most of the time.
Hope
Another possible solution could be giving permission to \wp-content\uploads\
folder; command: chmod -R 0755 wp-content\uploads\
.
Hope it may help you too.